Endovascular Treatment of Infrapopliteal Peripheral Artery Disease

Midterm Outcomes and Predictors of Failure of Lower Extremity Bypass to Para-Malleolar and Pedal Targets

BACKGROUND

The frequency of distal lower extremity bypass (LEB) for infrapopliteal critical limb threatening ischemia (IP-CLTI) has significantly decreased. Our goal was to analyze the contemporary outcomes and factors associated with failure of LEB to para-malleolar and pedal targets.

METHODS

We queried the Vascular Quality Initiative infrainguinal database from 2003 to 2021 to identify LEB to para-malleolar or pedal/plantar targets. Primary outcomes were graft patency, major adverse limb events [vascular reintervention, above ankle amputation] (MALE), and amputation-free survival at 2 years. Standard statistical methods were utilized.

RESULTS

We identified 2331 LEB procedures (1,265 anterior tibial at ankle/dorsalis pedis, 783 posterior tibial at ankle, 283 tarsal/plantar). The prevalence of LEB bypasses to distal targets has significantly decreased from 13.37% of all LEB procedures in 2003-3.51% in 2021 (P < 0.001). The majority of cases presented with tissue loss (81.25. Common postoperative complications included major adverse cardiac events (8.9%) and surgical site infections (3.6%). Major amputations occurred in 16.8% of patients at 1 year. Postoperative mortality at 1 year was 10%. On unadjusted Kaplan-Meier survival analysis at 2 years, primary patency was 50.56% ± 3.6%, MALE was 63.49% ± 3.27%, and amputation-free survival was 71.71% ± 0.98%. In adjusted analyses [adjusted for comorbidities, indication, conduit type, urgency, prior vascular interventions, graft inflow vessel (femoral/popliteal), concomitant inflow procedures, surgeon and center volume] conduits other than great saphenous vein (P < 0.001) were associated with loss of primary patency and increased MALE. High center volume (>5 procedures/year) was associated with improved primary patency (P = 0.015), and lower MALE (P = 0.021) at 2 years.

CONCLUSIONS

Despite decreased utilization, open surgical bypass to distal targets at the ankle remains a viable option for treatment of IP-CLTI with acceptable patency and amputation-free survival rates at 2 years. Bypasses to distal targets should be performed at high volume centers to optimize graft patency and limb salvage and minimize reinterventions.

Remodelers of the vascular microenvironment: The effect of biopolymeric hydrogels on vascular diseases

Vascular disease is the leading health problem worldwide. Vascular microenvironment encompasses diverse cell types, including those within the vascular wall, blood cells, stromal cells, and immune cells. Initiation of the inflammatory state of the vascular microenvironment and changes in its mechanics can profoundly affect vascular homeostasis. Biomedical materials play a crucial role in modern medicine, hydrogels, characterized by their high-water content, have been increasingly utilized as a three-dimensional interaction network. In recent times, the remarkable progress in utilizing hydrogels and understanding vascular microenvironment have enabled the treatment of vascular diseases. In this review, we give an emphasis on the utilization of hydrogels and their advantages in the various vascular diseases including atherosclerosis, aneurysm, vascular ulcers of the lower limbs and myocardial infarction. Further, we highlight the importance and advantages of hydrogels as artificial microenvironments.

Endovascular Interventions for Peripheral Artery Disease: A Contemporary Review

PURPOSE OF REVIEW

Peripheral artery disease (PAD) is an increasingly prevalent but frequently underdiagnosed condition that can be associated with high rates of morbidity and mortality. While an initial noninvasive approach is the cornerstone of management, revascularization is often pursued for patients with treatment-refractory claudication or chronic limb-threatening ischemia (CLTI). In this review, we discuss the current state of endovascular interventions for PAD and explore the many new emerging technologies.

RECENT FINDINGS

The last decade has resulted in numerous advances in PAD interventions including the ongoing evolution of drug-coated devices, novel approaches to complex lesions, and contemporary evidence from large clinical trials for CLTI. Advances in endovascular management have allowed for increasingly complex lesions to be tackled percutaneously. Future directions for the field include the continued evolution in device technology, continued development of state-of-the-art techniques to revascularization of complex lesions, and increased collaboration between a largely multidisciplinary field.

Peripheral Arterial Disease: A Narrative Review

Peripheral arterial disease (PAD) describes the partial or complete occlusion of blood flow in the distal arteries of the body. A decreased arterial patency may occur due to a reduction in the elasticity or diameter of the vessel. The goal of interventions is to decrease incidence and reduce complications by identifying and minimizing the primary causes. This paper discusses PAD affecting the aortoiliac, common femoral, and femoropopliteal arteries. In a significant portion of the population, PAD may lack usual symptoms such as limb pain, claudication, and diminished pulses. Imaging techniques become crucial to ensuring timely diagnosis, monitoring treatment effectiveness, and preventing recurrence. Duplex ultrasound (DUS) is a cheap and non-invasive preliminary technique to detect atherosclerotic plaques and grade arterial stenosis. Magnetic resonance angiography (MRA) provides the added advantage of minimizing artifacts. Digital subtraction angiography (DSA) remains the gold standard for grading the degree of stenosis but is only employed second-line to DUS or MRA due to the high dose of nephrotoxic contrast. Computed tomography angiography (CTA) is able to overcome the anatomical limitations of DUS and MRA and proves to be a suitable alternative to DSA in patients with renal disease. Preventative measures involve monitoring blood pressure, cholesterol levels, and tobacco usage. First-line treatment options include endovascular procedures as well as surgical interventions in cases of significant arterial involvement. Endovascular treatments involve the use of balloon angioplasty, drug-coated balloons, and drug-coated stents, to name a few, that serve as minimally invasive techniques to manage PAD. Surgical procedures, although more complex, are considered gold-standard treatment options for long and intricate lesions. Endovascular methods are generally preferred over surgical options as the complication risk is severely reduced and the rates of reintervention are comparable to surgical options.

Standard Balloon Angioplasty Versus Serranator Serration Balloon Angioplasty for the Treatment of Below-the-Knee Artery Occlusive Disease: A Single-Center Subanalysis From the PRELUDE-BTK Prospective Study

BACKGROUND

Endovascular interventions in infrapopliteal occlusive artery disease are becoming more complex, and this frequently tests the standard method of treatment, plain old balloon angioplasty (POBA). The potential that serration angioplasty could produce a more acceptable tibial artery lumen was assessed in this study.

AIM

The aim of this single-center subgroup analysis was to compare acute angiographic results after endovascular treatment using the Serranator serration balloon catheter in patients participating in the PRELUDE-BTK trial with POBA of the infrapopliteal arteries. A secondary objective was to assess post-treatment hemodynamic improvements.

METHODS

Our center enrolled 15 subjects and treated 17 lesions within the multicenter prospective core laboratory-adjudicated PRELUDE-BTK study. A 25 lesions analyzed separately were treated with POBA and then compared with the Serranator subset. In both cohorts, lesions were treated with either plain angioplasty or Serranator as a stand-alone therapy; subsequent methods, such as drug elution technologies, were not used. Acute angiographic results were analyzed by the SynvaCor angiographic core laboratory. To assess volumetric flow rates, data were analyzed with a fluid flow simulation software and compared against Poiseuille's Law.

RESULTS

Final residual stenosis was 17.2%±8.2% in the Serranator group versus 33.7%±15.7% in the POBA group. The mean lumen diameter (MLD) gain for the Serranator group and the POBA group was 1.64±0.41 mm and 1.33±0.63 mm, respectively. The average atmospheric balloon inflation pressure was 5 ATM in the Serranator group versus 9 ATM in the POBA group. Neither group required a bailout stent; however, it was notable that there were significantly more chronic total occlusions (CTOs) treated in the Serranator group at 41.2% versus 12% in the POBA group. Regarding the effectiveness in improving hemodynamic blood flow for non-CTO lesions, the calculated average ratio of post-treatment to pre-treatment flow rates in the Serranator group was 238% than that for the POBA group. For CTO cases where pre-treatment flow rate was zero, final residual stenosis was used as the parameter for comparison. The Serranator group showed a 62% improvement in final residual stenosis over POBA.

CONCLUSION

Endovascular treatment of the infrapopliteal arteries by use of the Serranator serration balloon provides a novel and promising method of action compared with standard balloon angioplasty and, thus, may have a leading role in complex below-the-knee arterial lesions.

CLINICAL IMPACT

The Serranator device might help to adequately address issues with conventional routine techniques for the treatment of complex lesions in infrapopliteal arteries in patients with advanced stages of PAD and critical limb ischemia. Integrating modern technologies such as the Serranator balloon catheter into clinical routine is mandatory in order to gain a more favorable outcome in these severely diseased patients and, particularly, to reduce mortality and morbidity.

Mortality Risk Assessment in Peripheral Arterial Disease-The Burden of Cardiovascular Risk Factors over the Years: A Single Center's Experience

Atherosclerosis is the basis of the cardiovascular continuum in peripheral artery disease (PAD) patients. Limiting functional decline and increasing quality of life are the main objectives for these patients. We conducted a prospective cohort study on 101 patients with PAD admitted to a single center in Northeast Romania. We used an index score to evaluate the 10-year mortality risk assessment and based on the scores we divided the patients into two groups: a low and low-intermediate risk mortality group (49 cases, 48.5%) and a high-intermediate and high-risk mortality group (52 cases, 51.5%). We analyzed demographics, comorbidities, clinical and paraclinical parameters and we aimed to identify the parameters associated with an unfavorable prognosis. Patients in the high-intermediate and high-risk mortality group were associated more with cardiovascular risk factors. Hypertension (p = 0.046), dyslipidemia (p < 0.001), diabetes mellitus (p < 0.001), and tobacco use (p = 0.018) were statistically significant factors. Lipid profile (low-density lipoprotein cholesterol, p = 0.005) and fasting blood glucose (p = 0.013) had higher mean serum values in the high-intermediate and high-risk mortality group, with a positive correlation between them and the ankle-brachial index value (p = 0.003). A multidisciplinary assessment and, especially, correction of associated cardiovascular risk factors prevent complications, and thus, improve the prognosis in the medium and long term.

Orbital Atherectomy Prior to Drug-Coated Balloon Angioplasty in Calcified Infrapopliteal Lesions: A Randomized, Multicenter Pilot Study

PURPOSE

Optimal balloon angioplasty for infrapopliteal lesions is often limited by severe calcification, which has been associated with decreased procedural success and lower long-term patency.

MATERIALS AND METHODS

This was a prospective, randomized, multicenter pilot trial that included adult subjects with calcified lesions located from the popliteal segment below the knee (BTK) joint to within 5 cm above the ankle with ≥70% diameter stenosis by angiography. Patients were randomized 1:1 to undergo orbital atherectomy (OA) with adjunctive drug-coated balloon (DCB) angioplasty versus plain balloon angioplasty (BA) and DCB angioplasty (control). The periprocedural and 12 month outcomes of both procedures were compared.

RESULTS

Overall, 66 subjects (OA + DCB = 32 vs control = 34) were included in an intention to treat analysis. Baseline demographics and lesion characteristics were well-balanced. The mean lesion length was 101.3 mm (SD = 72.8 mm) and 78.8 (SD = 61.0 mm) in the OA + DCB and control groups, respectively, with almost all lesions having severe calcification per the Peripheral Academic Research Consortium (PARC) criteria. Chronic total occlusions (CTOs) were present in 43.8% and 35.3% of the patients in the OA + DCB and control groups, respectively. The technical success of OA + DCB versus DCB was 81.8% and 89.2%, respectively, with 3 slow flow/no reflow, 1 perforation, 1 severe dissection occurred in OA + DCB group, and one distal embolization occurred in the control group. The target lesion primary patency rate was numerically higher in the OA + DCB versus control group at 6 (88.2% vs 50.0%, p=0.065) and 12 month follow-up (88.2% vs 54.5%, p=0.076). The 12 month freedom from major adverse events, clinically-driven target lesion revascularization, major amputation, and all-cause mortality rates were similar between both groups.

CONCLUSION

The results of the Orbital Vessel PreparaTIon to MaximIZe Dcb Efficacy in Calcified BTK (OPTIMIZE BTK) pilot study indicated that utilization of OA + DCB is safe for infrapopliteal disease. Further prospective adequately powered studies should investigate the potential benefit of combined OA + DCB for BTK lesions.

Anterior, posterior, or all-vessel infrapopliteal revascularization in patients with moderate-severe claudication: Insights from the LIBERTY 360 study

BACKGROUND

Little data guides revascularization of infrapopliteal peripheral arterial disease (PAD) in patients with claudication. We assessed outcomes after infrapopliteal-only intervention for claudication in the LIBERTY 360 observational study.

METHODS

In this post hoc analysis, LIBERTY 360 patients (N = 128) with claudication and isolated infrapopliteal disease undergoing endovascular revascularization were divided by territory into anterior-vessel, posterior-vessel, or all-vessel groups. Patients were followed for periprocedural, in-hospital, and long-term outcomes. Logistic regression for odds ratios, Cox proportional hazard models, ANOVA, and Kaplan-Meier estimates were utilized to compare outcomes.

RESULTS

Patients underwent anterior (N = 37), posterior (N = 76), or all-vessel (N = 15) infrapopliteal revascularization. Initial procedural success was 86%, 86%, and 69% for anterior, posterior, and all-vessel groups, respectively. Each group had improvements in Rutherford classification (RC) from baseline to 2 years (mean RC change: -1.3, -1.5, and -1.5, respectively). Compared with all-vessel intervention, both anterior and posterior groups had lower rate of major adverse events (MAE) and target vessel revascularization (TVR) at 3 years (MAE: 12% and 15% in anterior and posterior groups, respectively compared with 51% in the all-vessel group; hazard ratios and 95% CIs 0.22 [0.06-0.74], p = .015; 0.24 [0.09-0.64], p = .004). Other outcomes were similar among the three groups. The anterior group showed more improvement in pain subdomain and total VascuQoL scores compared with posterior and all-vessel groups at 2 years (p = .016, p = .020 and p = .068, p = .009, respectively).

CONCLUSIONS

Both anterior or posterior revascularization have favorable outcomes and may be beneficial for improvement of symptoms in claudicants with isolated infrapopliteal PAD.

[General Treatment Strategy for Intervention in Lower Extremity Arterial Disease]

The prevalence of lower extremity disease is increasing with age. With recent technological advancements, endovascular treatment is being performed more frequently. The treatment goal of intermittent claudication is to improve walking and reduce claudication. To achieve these goals, anatomical durability and patency are important. In patients with critical limb ischemia, the lesions are diffuse and particularly severe in below-the-knee arteries. The treatment goal of critical limb ischemia is to promote wound healing and to prevent major amputation, which is evaluated by the limb salvage rate. Primary stenting using covered or bare metal stents is a widely accepted endovascular treatment. While drug-eluting technologies with or without atherectomy are widely used in the treatment of femoropopliteal disease, balloon angioplasty is the mainstay treatment for below-the-knee intervention. CT angiography provides a road map for planning endovascular treatment in patients without absolute contraindications.

Balloon Angioplasty of Infrapopliteal Arteries: A Systematic Review and Proposed Algorithm for Optimal Endovascular Therapy

Endovascular revascularization has been increasingly utilized to treat patients with chronic limb-threatening ischemia (CLTI), particularly atherosclerotic disease in the infrapopliteal arteries. Lesions of the infrapopliteal arteries are the result of 2 different etiologies: medial calcification and intimal atheromatous plaque. Although several devices are available for endovascular treatment of infrapopliteal lesions, balloon angioplasty still comprises the mainstay of therapy due to a lack of purpose-built devices. The mechanism of balloon angioplasty consists of adventitial stretching, medial necrosis, and dissection or plaque fracture. In many cases, the diffuse nature of infrapopliteal disease and plaque complexity may lead to dissection, recoil, and early restenosis. Optimal balloon angioplasty requires careful attention to assessment of vessel calcification, appropriate vessel sizing, and the use of long balloons with prolonged inflation times, as outlined in a treatment algorithm based on this systematic review. Further development of specific devices for this arterial segment are warranted, including devices for preventing recoil (eg, dedicated atherectomy devices), treating dissections (eg, tacks, stents), and preventing neointimal hyperplasia (eg, novel drug delivery techniques and drug-eluting stents). Further understanding of infrapopliteal disease, along with the development of new technologies, will help optimize the durability of endovascular interventions and ultimately improve the limb-related outcomes of patients with CLTI.

Antiplatelet therapy for tibial balloon angioplasty: A clinical perspective

Percutaneous transluminal tibial balloon angioplasty has an important role in the therapeutic approach of critical limb ischaemia. Despite a growing number of patients with critical limb ischaemia, there are no trials to guide the pharmacologic approach post intervention. Guidelines pertaining to the antiplatelet therapy post percutaneous transluminal tibial balloon angioplasty have not been developed. In addition, critical limb ischaemia patients have multiple comorbidities and a higher risk of bleeding. To examine the shortest duration of antiplatelet therapy post percutaneous transluminal tibial balloon angioplasty, we reviewed the preclinical data used to develop the standards for the current angioplasty technique.

Prior Endovascular Intervention Is Not Detrimental to Pedal Bypasses for Ischemic Wounds

BACKGROUND

Endovascular strategies are often preferred for revascularization of ischemic foot wounds secondary to infrapopliteal disease because of the less invasive technique and faster recovery. Bypass is typically reserved for failures or lesions not amenable to balloon angioplasty. However, the effects of an endovascular-first approach on subsequent bypass grafts are largely unknown. This study evaluates the effects of prior endovascular tibial interventions (PTIs) on successive bypasses to pedal targets.

METHODS

Patients who presented with ischemic tissue loss and tibial arterial occlusive disease to University of Pittsburgh Medical Center between 2006 and 2013 and underwent a surgical bypass to pedal arteries were included in this study. A retrospective chart review was conducted to obtain patient demographics, past medical history, extent of disease, prior tibial endovascular interventions, the treatment intervention, subsequent interventions, wound healing status, limb salvage, and patient survival. The primary outcome was primary patency of the pedal bypass graft.

RESULTS

From 122 eligible patients, 27 had a PTI, whereas 95 had no prior endovascular tibial intervention (nPTI) in the treatment of ischemic pedal wounds with mean follow-up of 24.5 and 20.5 months, respectively (P = 0.36). The 2 groups were largely similar in terms of demographics, comorbidities, wound size, and degree of ischemia. Runoff scores between the 2 groups were also comparable (5.0 ± 1.6 for PTI and 4.8 ± 1.9 for nPTI, P = 0.59). The plantar artery was a more common target vessel in the PTI group, whereas the posterior tibial artery was targeted more often in the nPTI group (P = 0.04). At 12 months, those with a PTI exhibited a shorter primary patency (34.8% vs. 60.2%, P = 0.04). In a multivariate model, PTI was a significant risk factor for primary patency loss (hazard ratio 2.51, P = 0.004). Primary assisted patency and secondary patency were similar between the 2 groups. Wound healing was improved in those patients who had a prior endovascular intervention with 63.8% healed at 1 year compared with only 34.8% of those without intervention (P = 0.01). Amputation-free survival was similar (P = 0.68), as was survival alone (P = 0.50).

CONCLUSIONS

Despite a decrease in primary patency, pedal bypass was not otherwise negatively affected by a PTI. Similar primary assisted patency, secondary patency, wound healing, and survival between the 2 patient populations indicate that an endovascular-first approach is a feasible treatment strategy to achieve similar clinical outcomes in the management of ischemic foot wounds.

Bypass versus endovascular intervention for healing ischemic foot wounds secondary to tibial arterial disease

OBJECTIVE

Pedal (inframalleolar) bypass is a long-standing therapy for tibial arterial disease in patients with ischemic tissue loss. Endovascular tibial intervention is an appealing alternative with lower risks of perioperative mortality or complications. Our objective was to compare the effectiveness of these two treatment modalities with respect to patency and limb-related clinical outcomes.

METHODS

We performed a retrospective chart review of patients presenting between 2006 and 2013 with ischemic foot wounds and infrapopliteal arterial disease who underwent a revascularization procedure (either open surgical bypass to an inframalleolar target or endovascular tibial intervention). Data were collected on baseline demographics and comorbidities, procedural details, and postprocedure outcomes. The primary outcome was successful healing of the index wound, with mortality, major amputation, and patency assessed as secondary outcomes.

RESULTS

We identified 417 patients who met our eligibility criteria; 105 underwent surgical bypass and 312 underwent endovascular intervention, with mean follow-up of 25.0 and 20.2 months, respectively (P = .08). The endovascular patients were older at baseline (P = .009), with higher rates of hyperlipidemia (P = .02), prior cerebrovascular accidents (P = .04), and smoking history (P = .04). Within 30 days postoperatively, there was no difference in mortality (P = .31), but bypass patients had longer hospital length of stay (P < .0001), higher rate of discharge to nursing facility (P < .001), and higher rates of myocardial infarctions (P = .03) and wound complications (P < .001). At 6 months, the rate of wound healing was 22.4% in the bypass group compared with 29.0% in the endovascular group (P = .02). At 1 year, survival was higher after bypass (86.2% vs 70.4%; P < .0001), but freedom from major amputation was similar (84.9% vs 82.8%; P = .42). Primary patency (53.1% vs 38.2%; P = .002) and primary assisted patency (76.6% vs 51.7%; P < .0001) were higher in the bypass group, but there was no difference in secondary patency (77.3% vs 73.8%; P = .13).

CONCLUSIONS

Endovascular tibial intervention is associated with poorer primary patency but similar secondary patency and wound healing rates compared with the "gold standard" of surgical bypass to a pedal target. In patients with tibial arterial disease, endovascular intervention should be considered a lower risk alternative to pedal bypass that provides similar clinical outcomes.

[Endovascular surgery for critical ischemia of lower extremities with suppurative-necrotic lesion of the feet]

AIM

To improve treatment of patients with grade IV chronic ischemia of lower extremities via endovascular angioplasty combined with surgical methods for suppurative-necrotic lesions of the feet.

MATERIAL AND METHODS

51 patients with grade IV chronic ischemia of lower extremities underwent endovascular interventions (balloon angioplasty, stenting). A total of 23 stents were deployed in 16 patients including 12 stents in superficial and common femoral arteries, 5 in popliteal artery, 6 in iliac artery. There were no stents in crural arteries. The most perspective artery for wound healing was preferred in case of revascularization below popliteal segment. Necrectomy was performed along with angioplasty in patients with suppurative-necrotic lesion of the feet followed by delayed reconstructive operations if it was necessary.

RESULTS

Endovascular surgery for grade IV chronic ischemia of lower extremities was associated with good immediate results in most cases due to revascularization and organ-sparing interventions for suppurative lesions of the feet. Current endovascular methods allow to perform successful re-operations to restore blood flow in previously repaired arteries and implanted stents with restenosis or thrombosis.